Scalpels are regularly used by surgeons and other health care professionals for making incissions during an operating procedure. Typically, the operating room assistant passes a scalpel or other surgical instrument to the surgeon's hand in a predetermined orientation, so that the surgeon can grasp the instrument and automatically grip the handle without taking his or her eyes away from the patient or the instrumentation. If the instrument includes a sharp cutting edge or point, it is possible that the surgeon's hand may be cut or nicked in the instrument transfer. Because of such a possibility, sclapels and other surgical instruments have been developed that make the surgical instrument "safe" by keeping the sharp or pointed portion of the instrument enclosed in some form of a sheath during the transfer from the operating room assistant to the surgeon, the surgeon then unsheaths the instrument for use during the operation. The same possible cut or nick can occur during the return of the instrument from the surgeon to the operating room assistant, so it is desireable that the instrument be resheathed for the return transfer.
The concern over possible cuts or nicks has become especially acute since the appearance of the human immune deficiency virus (HIV) as well as other virus such as the Hepatitis B virus (HBV). In some cases, surgeons have stopped performing operations rather than risk the chance of inadvertently being exposed to these viruses.
Several forms of sheathing and sclapel protecting apparatus have been disclosed, some using sliding sheaths and others providing rotatable sheaths to cover the scalpel's cutting surface. One form of such a guard is shown in U.S. Pat. No. 5,330,493, Haining; 5,330,492, Haugen, and 5,275,606, Abidin et al, where a scalpel is enclosed in a guard and a finger operated portion is used to advance and retact the blade form the guard. Each of these patents disclose a advance/retraction mechanism that is reciprocal without rotary movement of a cylindrical instument or sheath. U.S. Pat. Nos. 5,391,177, Schwartz; 5,309,641, Wonderly et al; 4,674,500, DeSatnick; 4,576,164, Richeson; and 4,499,898, Knepshield et al show surgical instruments that include cylindrical sheaths or covers for cutting elements and means for moving the cutting element into and out of the sheath or cover. Of these cylindrical sheath patents, the Richeson, the DeSatnick and the Schwartz disclosures include some form of slot and pin configuration that is reciprocated and rotated to move the functional part of the instrument from the sheathed position to the unsheathed position. In each of the instruments the rotational movement must be reversed to retrieve the instrument to its sheathed position.
The safety surgical instrument of the present invention includes a one-hand operating mechanism that can be used to move a sheathed surgical instrument from its sheathed position to its unsheathed position and the return to the sheathed position by a combination of rotational movement and longitudinal movement with the rotational movement in one direction of rotation only. The instrument includes locking positions in the sheathed position and in the unsheathed position.